Progress 09/01/23 to 08/31/24
Outputs
Target Audience:The target audiences of this reporting period were one female graduate student, one male undergraduate studnet, chemical and biotechnology companies (such as Sigma Aldrich, Fischer Scientific, and VWR), our industry partners, including Cereals Canada (previously known as Canadian International Grains Institute) and Richardson Centre for Food Technology and Research at the University of Manitoba as well as scientific community audiences of food engineers and food scientists. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?During this reporting period, one graduate student (Sama Ghadiri Gargari_ Ph.D. level) and one undergraduate student ( Gideon Boadu) participated in this research project on developing the tribo-electrostatic separation technology for legumes and cereals and assessing the resulting fractions for their rheological behavior and 3D food printing. The PI directly mentored students by providing not only scientific skills but also professional development and communication skills, the details of which are summarized below: All students attended and satisfied the annual mandatory laboratory safety orientation held by the College of Engineering and Architecture (CEA) at Howard University. My undergraduate student contributed to developing a water-free tribo-electrostatic separation (TES) approach and exploring agro-materials' tribo-charging behavior based on their physiochemical and operational conditions. My PhD student developed experiences in assessing the electrostatically enriched fractions' rheological properties and their use in 3D food printing, then linking the obtained rheological properties to 3D printing. She presented her results at AIChE annual meeting in October 2024 as well as during Howard University Research Month in April 2024 During this reporting period, my PhD student developed expertise in extrusion-based 3D food printing, steady shear tests, frequency sweep tests, recovery tests, and stress sweep dynamic tests. During this reporting period, my undergraduate student developed expertise in electrostatic separation technology, tribo-charge measurement techniques, and compositional analysis (protein and starch). My PhD student is in her fourth year (she joined my lab in early August 2021) and is expected to graduate in August 2025. She attended weekly in-person meetings to present her experimental and statistical modeling results and attended workshops on career advising and CV preparation. She has prepared and submitted two journal manuscripts (Journal of Food Engineering and Food Research International Journal) on the results obtained as part of yellow pea electrostatic separation optimization and tribo-charging behavior of protein and starch individual particles based on combined effects of particle dosing rate and airflow rates. We are currently awaiting the revision results of those submitted manuscripts. My PhD student has also prepared another manuscript on the separation behavior of protein-starch mixtures under both laminar and turbulent flow using different tribo-charging materials, which is now under the final steps of review for submission to the "Separation and Purification Technology" journal. How have the results been disseminated to communities of interest?**We have submitted two journal manuscripts to the Food Engineering Journal and Food Research International which are now underreview after first revision: 1) Ghadiri Gargari, S., Thomas, J., Rajabzadeh, A.R., Tabtabaei, S.(2024) Advancing Sustainable Protein Enrichment: Insights and Pathways from Integrated Milling and Tribo-Electrostatic Separation of Yellow Pea". Journal of Food Engineering, SUBMITTED UNDER REVISION. JFOODENG-D-24-01640R1. 2) Ghadiri Gargari, S., Tabtabaei, S. (2024). Combined Effects of Particle Dosing Rate and Airflow Rate on Triboelectric Charging of Wheat and Yellow Pea Protein and Starch. Food Research International, SUBMITTED UNDER REVISION, FOODRES-D-24-09550R1. **I have presented the results obtained as part of Objectives 1, 2, and 4 as a keynote speaker during the 5th Annual Research Spotlight Meeting of the Plant Protein Innovation Center (PPIC) at the University of Minnesota, Minneapolis, MN (May 22, 2024). 1) Tabtabaei, S. (2024) Electrostatically enriched plant proteins and their application in 3D food printing. Plant Protein Innovation Center (PPIC) - 5th Annual Research Spotlight Meeting (Invited Presentation). Minneapolis, MN (May 22, 2024). **Other Conference presentations include the presentation of two abstracts through Oral presentations at the 2024 AOCS annual meeting and Expo, one oral presentation during the 2024 AIChE Annual meeting, and one poster presentation during the 2024 Howard University Research Month. These presentations are listed below: 1) https://aiche.confex.com/aiche/2024/meetingapp.cgi/Paper/691909 2) Tabtabaei, S., Ghadiri Gargari, S., (2024). The Correlation between Tribo-charging of Agricultural Particles and their Classification Behavior via the Tribo-electrostatic Separation Approach (Oral Presentation). AOCS Annual Meeting and Expo, Montreal, QC (April 28, 2024) 3) Tabtabaei, S. (2024) Electrostatically enriched plant proteins and their application in 3D food printing. Plant Protein Innovation Center (PPIC) - 5th Annual Research Spotlight Meeting (Invited Presentation). University of Minnesota, Minneapolis, MN (May 22, 2024) 4) Ghadiri Gargari, S., Tabtabaei, S. (2024). Rheological behavior of protein-enriched 3D-printed snacks from yellow pea (Poster). Howard University Research Month, Washington DC (April 26, 2024) What do you plan to do during the next reporting period to accomplish the goals?The majority of the tasks proposed under Objectives 1, 2, and 4 have been finalized. I have hired two more graduate students on this project (one master level and one PhD level), starting August 2024. One of the graduate students has started assessing the functional properties of all yellow pea protein-rich fractions collected as part of Objective 2 and assessing those based on milling conditions and electrostatic operating conditions. The other graduate students are finalizing the 3D printing and rheological property results of the yellow pea electrostatically enriched protein fractions. During this last year of the project, we plan to establish functional-rheological-printability properties of all electrostatically enriched protein fractions and prepare two journal manuscripts from the results. ?
Impacts
What was accomplished under these goals?
During this reporting period, a great effort was made to prepare three journal manuscripts on the results obtained as part of Objectives 1 and 2. Two of these manuscripts, listed below, have been submitted to the Journal of Food Engineering and Food Research International, and the last one, which we plan to submit to the journal Separation and Purification Technology, is under final revision and review. Besides manuscript preparation, we have finalized most tasks proposed as part of Objective 4 by assessing the protein-starch mixtures' extrudability, rheological properties, and printability. As part of this task, yellow pea protein and starch isolates were combined in different ratios (ranging from 1:9 to 9:1 protein to starch) to create model legume mixtures. The goal was to determine the ideal protein-starch mixture and water content for extrusion-based 3D printing without additives. The ease of extrusion, shape stability after printing, and the outcome of post-processing cooking steps were assessed and correlated to the rheological characteristics of yellow pea pastes. All pastes demonstrated shear thinning behavior, including optimally formulated and unsuitable pastes for 3D printing. No specific threshold was observed to distinguish the most effective pastes from those clogging the nozzle or expanding after printing based on their storage and loss modulus. Pastes containing identical amounts of solid and water contents but with higher protein concentration exhibited elevated complex viscosity, indicating the demand for more water in protein-rich compositions to achieve optimal results in 3D printing. Greater height was achieved through 3D printing of protein-rich pastes due to their higher yield stress during stress sweep tests. This accounted for the higher deformation of starch-rich pastes after cooking as the post-processing step. The starch-rich pastes experienced a lower water loss rate, leading to a softer structure upon baking than those enriched with protein. Our recent results provided valuable insights into optimizing the paste formulation of legume-based ingredients in 3D printing and achieving desired textural and structural attributes in printed food products.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2024
Citation:
https://aiche.confex.com/aiche/2024/meetingapp.cgi/Paper/691909
- Type:
Other Journal Articles
Status:
Submitted
Year Published:
2024
Citation:
Ghadiri Gargari,S., Thomas, J., Rajabzadeh, A.R., Tabtabaei, S.(2024) Advancing Sustainable Protein Enrichment: Insights and Pathways from Integrated Milling and Tribo-Electrostatic Separation of Yellow Pea . Journal of Food Engineering, SUBMITTED UNDER REVISION. JFOODENG-D-24-01640R1
- Type:
Other Journal Articles
Status:
Submitted
Year Published:
2024
Citation:
Ghadiri Gargari, S., Tabtabaei, S. (2024). Combined Effects of Particle Dosing Rate and Airflow Rate on Triboelectric Charging of Wheat and Yellow Pea Protein and Starch. Food Research International, SUBMITTED UNDER REVISION, FOODRES-D-24-09550R1
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2024
Citation:
Tabtabaei, S., Ghadiri Gargari, S., (2024). The Correlation between Tribo-charging of Agricultural Particles and their Classification Behavior via the Tribo-electrostatic Separation Approach (Oral Presentation). AOCS Annual Meeting and Expo, Montreal, QC (April 28, 2024)
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2024
Citation:
Ghadiri Gargari, S., Tabtabaei, S. (2024). Tribo-charging and separation behaviors of protein-starch mixtures derived from legumes and cereals (Oral Presentation). AOCS Annual Meeting and Expo, Montreal, QC (April 29, 2024)
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2024
Citation:
Tabtabaei, S. (2024) Electrostatically enriched plant proteins and their application in 3D food printing. Plant Protein Innovation Center (PPIC) - 5th Annual Research Spotlight Meeting (Invited Presentation). University of Minnesota, Minneapolis, MN (May 22, 2024)
Abstract:
Tribo-electrostatic separation (TES) is a waste-free approach to dry fractionation of milled legumes, cereals, and oilseed meals, producing functional protein concentrates. Through TES, milled particles of agro-materials are charged using tribo-charger tubes of different materials through pneumatic transfer and fractionated under an electric field. The uniform particle size distribution of dietary fiber and protein particles restricted the protein enrichment in cereal groats and oilseeds compared to legumes. The TES analysis on binary mixtures of protein-starch and protein-fiber showed that the initial protein content plays a crucial role in high protein enrichment. Enriched legume proteins exhibited superior rheological and viscoelastic properties as 3D printing materials for healthy snacks.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2024
Citation:
Ghadiri Gargari, S., Tabtabaei, S. (2024). Rheological behavior of protein-enriched 3D-printed snacks from yellow pea (Poster). Howard University Research Month, Washington DC (April 26, 2024)
ABSTRACT:3D food printing is a potential emerging technique for creating customized nutritional foods. Understanding the impact of individual components on the nutritional and structure of 3D-printed foods is crucial for their strategic development and applications. This study evaluated the viability of using yellow pea protein-rich and starch-rich pastes in extrusion-based 3D food printing. Yellow pea protein and starch mixtures with different compositions were prepared and blended with water without additional additives to assess their ease of extrusion and shape stability after printing and heating. The 3D printing results were then correlated with their rheological behaviors. All pastes exhibited shear-thinning characteristics, including the most efficient and unsuitable pastes for printing. The efficient pastes had an intermediate level of storage and loss modulus compared to the pastes incapable of being extruded uniformly or preserving their shape. However, there was no specific threshold to classify them as suitable 3D printing materials. At the equivalent amounts of solid mixture and water, increasing the protein content of the mixture enhanced the complex viscosity of pastes, necessitating more water in protein-rich mixtures to improve their printability. The best-performing starch-rich pastes experienced a notable rise in their storage modulus at temperatures above 70�C, suggesting using an additive to enhance their stability during cooking post-processing. The provided data may help fortify the nutritional qualities of 3D food printing materials and offer valuable insights into the critical rheological parameters contributing to effective extrusion-based 3D printing.
|
Progress 09/01/22 to 08/31/23
Outputs
Target Audience:The target audiences of this reporting period were one female graduate student, chemical and biotechnology companies (such as Sigma Aldrich, Fischer Scientific, and VWR), our industry partners, including Cereals Canada (previously known as Canadian International Grains Institute) and Richardson Centre for Food Technology and Research at the University of Manitoba as well as scientific community audiences of food engineers and food scientists. Changes/Problems:We plan to request a no-cost extension for one year to fully accomplish all tasks proposed under Objectives 3 and 4.I have recruited one additional Ph.D. student on this project who wassupposed to start in September 2023, but her starting date was delayed to 2024 due to the Student Visa administrative process. What opportunities for training and professional development has the project provided?During this reporting period, one graduate student (Sama Ghadiri Gargari_ Ph.D. level) participated in this research project on developing the tribo-electrostatic separation technology for legumes and cereals. The PI directly mentored her by providing not only scientific skills but also professional development and communication skills, the details of which are summarized below: My Ph.D. student attended and satisfied the annual mandatory laboratory safety orientation held by the College of Engineering and Architecture (CEA) at Howard University. She contributed to developing a water-free tribo-electrostatic separation (TES) approach and exploring agro-materials' tribo-charging behavior based on their physiochemical and operational conditions. During this reporting period, she developed expertise in electrostatic separation technology, tribo-charge measurement techniques, compositional analysis (protein and starch), SEM analysis, and particle size measurement techniques. She was trained and performed preliminary research on biochemical analysis (SDS-PAGE), food functionality (protein solubility, emulsifying, and foaming properties), and 3D food printing on the electrostatically enriched protein fractions. Following this preliminary research, we plan to finalize the 3D food printing of the protein products starting January 2024. She also developed expertise in using SAS software to statistically analyze and optimize the experimental results obtained in my lab for publication. My PhD student is in her third year (she joined my lab in early August 2021). She completed her written and oral Ph.D. qualification exam in July 2023 and plans to graduate by May 2025. She attended weekly in-person meetings to present her experimental and statistical modeling results and attended workshops on career advising and CV preparation. She has published two journal manuscripts (Powder Technology Journal and INFORM magazine of AOCS) on optimizing plant protein enrichment through the TES approach. She has recently finalized the preparation of three more manuscripts on the charging and separation behavior of model cereal and legume binary mixtures at laminar and turbulent gas flow rates that we plan to submit to reputable journals in early 2024. She has also presented her computational and experimental results at three conferences, including the 2023 AOCS and 2023 AIChE Annual Meetings and the Howard University Research Symposium (April 2023). How have the results been disseminated to communities of interest?The results on optimizing yellow pea protein enrichment through the tribo-electrostatic separation (TES) process (Objective 2) have been published in "Powder Technology Journal" and presented at two different conferences, including the Howard University Research Symposium (April 2023) and the AOCS Annual Meeting in Denver (May 2023). Another journal manuscript has also been prepared, based on the separation and charging behavior of milled yellow pea flour, which we plan to finalize and submit in early 2024. • Jamaka Thomas, Sama Ghadiri Gargari, Solmaz Tabtabaei (2023). "Tribo-electrostatic separation of yellow pea and its optimization based on milling types and screen sizes," Powder Technology (415) 118169. https://doi.org/10.1016/j.powtec.2022.118169. • Ghadiri Gargari, S., S. Tabtabaei (2023). Tribo-electrification Behavior of Milled Yellow Pea Powders. Howard University Research Month (April 27), Washington, DC, USA (Poster Presentation). • Ghadiri Gargari, S., S. Tabtabaei (2023). Separation behavior of yellow pea flour through a combined milling and tribo-electrostatic separation approach. AOCS Annual Meeting, Denver, CO, USA, May 1 (Oral Presentation). The results on the charging and separation behavior of model binary mixtures of legumes and cereals (Objectives 1 and 2) were presented at the 2023 AIChE Annual Meeting in Orlando in November 2023, as listed below. Based on model binary mixtures' charging and separation behavior at the laminar and turbulent gas flow rates, we have prepared two more journal manuscripts we plan to finalize and submit in early 2024. • Ghadiri Gargari, S., S. Tabtabaei (2023). Tribo-Charging and Separation Behavior of Milled Yellow Pea Flour and Plant Protein-Starch Mixture Models. AIChE Annual Meeting, Orlando, FL, USA, November 8 (Oral Presentation). https://aiche.confex.com/aiche/2023/meetingapp.cgi/Paper/670170 What do you plan to do during the next reporting period to accomplish the goals?Now that the results of Objectives 1 and 2 have been finalized, we will start the experiments on assessing the food functionality and 3D printing behavior of the fractionated yellow pea and oat flours (Objectives 3 & 4). Our 3D food printer was purchased and fully set up in the lab. My PhD student was fully trained to use the instrument. We did communicate with the Richardson Centre for Food Technology and Research at the University of Manitoba to receive pin-milled wheat, oats, yellow pea, and lentil flour. We will assess the functionality- rheology-printability correlation among different fractions while assessing the effect of drying on 3D-printed protein-rich samples in the last year of the project.
Impacts
What was accomplished under these goals?
During the 2022-2023 reporting period, we fully accomplished the tasks proposed in Objectives 1 and 2. To effectively examine the tribo-charging behavior of single-component protein and starch particles, we started by interrogating the chargeability of single-component protein and starch under different operational conditions. To achieve this goal, we set up a fluidized bed connected to the Faraday cup to pneumatically flow particles through tribo-charger tubes of different sizes and materials to effectively assess the role of air flow rate, powder dosing rate, tribo-charger size, and material. Model protein and starch particles (aw ≈ 0) were initially placed in the fluidized bed on top of the air distributor screen. Dry air was introduced at the bottom of the bed to pass the suspended particles into the tribo-charger tube before dispensing them into a Faraday cup connected to an electrometer for specific charge (nC/g) measurements. These charge measurement studies were performed at laminar and turbulent airflow rates of 7 and 12 LPM using 50-cm, 105-cm, and 150-cm nylon, copper, PVC, and PTFE tubes with 3/16" internal diameter. The results showed different chargeability of particles using different materials. All particles acquired the highest charge-to-mass ratios at lower particle concentrations inside the tubes. Both protein and starch particles were charged negatively in contact with nylon; starch obtained the most significant negative charge in contact with nylon material. All starch particles were charged negatively in contact with copper, while protein particles acquired positive charges. All particles charged positively in contact with PVC and PTFE, but protein particles acquired significantly higher charge-to-mass ratios (nC/g) than starch granules. We have also analyzed the particle sizes of all model binary mixtures to be able to convert specific charge values (nC/g) to charge density values (nC/m2) to clearly understand the relevance of charge to particle size vs. surface chemistry. In addition to analyzing the particle size of the single-model particles, we prepared model binary mixtures of yellow pea protein and starch as legume representatives, as well as model binary mixtures of wheat protein and starch as cereal representatives. All binary mixtures were prepared at different protein: starch weight ratios ranging from 1:1 to 9:1 and analyzed for charge measurement at laminar and turbulent airflow rates using different tribo-charging materials of PVC, PTFE, Nylon, and Copper. After charge analysis, all binary mixtures were separated through TES under both laminar and turbulent airflow rates at relatively high plate voltages obtained as optimum values during our previous optimization studies (last reporting periods). The results indicated that the protein enrichment of binary mixtures is highly dependent on the initial protein content of the starting mixtures and is independent of the material being used for changeability. The results were summarized in two journal manuscripts we plan to finalize and submit in early January 2024. Other than these extensive fundamental studies in chargeability and electrostatic separation of binary protein-starch mixtures, we have conducted preliminary research on assessing the 3D printability of the electrostatically separated protein fractions, and we plan to expand these studies to the variety of fractions in 2024.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2023
Citation:
Ghadiri Gargari, S., S. Tabtabaei (2023). Separation behavior of yellow pea flour through a combined milling and tribo-electrostatic separation approach. AOCS Annual Meeting, Denver, CO, USA, May 1 (Oral Presentation).
ABSTRACT: This study combined milling and tribo-electrostatic separation (TES) processes to assess the protein enrichment from yellow pea flour in a sustainable, non-destructive way. Before the TES process, the flour was milled using the pin and Ferkar milling systems equipped with 0.14- and 0.5-mm screen sizes. The samples were then tribo-charged under 7 to 14 LPM airflow rates and fractionated by being exposed to two parallel charged plates holding electric field strengths of �3 to �12 kV. The flours collected from the positively charged plate (PCP) and chamber bottom (CB) were protein-depleted, whereas the negatively charged plate (NCP) mainly attracted protein particles. In this study, we have assessed the effect of milling types and intensity, along with airflow rate and plate voltages, on the NCP fractions physiochemical properties and their composition, yield, and protein recovery. Applying laminar flow (7 LPM) and average plate voltage (�6.5 kV) to 0.14-mm pin-milled flour led to the production of optimal protein concentrate. As a result, the flours protein was enriched from 19.9 to 57%, accounting for 62% protein recovery. In addition, the 0.14-mm pin-milled flour had the smallest average particle size (D50), causing its protein particles to collide and gain more charge, enhancing protein enrichment of the NCP fractions. While the yield and protein recovery of the NCP fractions was higher under a strong electric field, adjusting to a higher plate voltage led to quick electrode fouling. It also attracted weakly-charged protein-fiber matrices of the cell wall to the NCP fraction rather than the CB fraction, making plate voltage ineffective for improving protein enrichment.
According to SEM images of all electrostatically-separated fractions under different airflow rates, many starch granules, which had been attracted to the PCP fraction at laminar flow, agglomerated with overcharged protein particles at turbulent flow and ended up in the NCP fraction, thereby reducing its protein enrichment and increasing its average particle size (D50). This optimization study produced uniformly sized yellow pea protein concentrate with high protein and retained bio-functionality, suitable as a novel ingredient in food production systems.
Acknowledgment: The authors acknowledge USDA-NIFA-AFRI (Bioprocessing & Bioengineering) Award#2020-67021-31141 for its support.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2023
Citation:
https://aiche.confex.com/aiche/2023/meetingapp.cgi/Paper/670170
Ghadiri Gargari, S., S. Tabtabaei (2023). Tribo-Charging and Separation Behavior of Milled Yellow Pea Flour and Plant Protein-Starch Mixture Models. AIChE Annual Meeting, Orlando, FL, USA, November 8 (Oral Presentation).
- Type:
Journal Articles
Status:
Published
Year Published:
2023
Citation:
Jamaka Thomas, Sama Ghadiri Gargari, Solmaz Tabtabaei (2023). "Tribo-electrostatic separation of yellow pea and its optimization based on milling types and screen sizes", Powder Technology (415) 118169.
https://doi.org/10.1016/j.powtec.2022.118169.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2023
Citation:
Ghadiri Gargari, S., S. Tabtabaei (2023). Tribo-electrification Behavior of Milled Yellow Pea Powders. Howard University Research Month (April 27), Washington, DC, USA (Poster Presentation)
ABSTRACT: To address the projected global hunger by 2050, sustainable plant-based proteins necessitate replacing or complementing animal-based proteins. This study combined the milling and tribo-electrostatic separation approaches to assess protein enrichment from yellow pea flour. Yellow pea was milled using pin and Ferkar milling systems equipped with 0.14- or 0.5-mm screen sizes. The milled flours were then pneumatically transferred into a Polytetrafluoroethylene tribo-charger tube at flowrates of 714 LPM and fractionated by two oppositely-charged plates holding �3 to �12 kV voltages in the fractionation chamber. The negatively charged plate (NCP) attracted protein, whereas the flours on the positively charged plate (PCP) and chamber bottom (CB) were starch-enriched. Based on General Linear Models, laminar flow (7 LPM) and moderate plate voltage (�6.5 kV) produced optimal protein concentrate using 0.14-mm pin-milled flour. This condition recovered 62% protein and increased protein content from ~20 to 57%. Regardless of screen size, particles obtained higher specific surface area through pin milling. Hence, 0.14-mm pin-milled flour acquired the highest charge by collision, allowing for greater attraction of protein particles to NCP fraction. Plate voltage increased the NCP fraction's protein recovery but was ineffective on protein content due to electrode fouling at strong electric fields. Most of the starch granules attracted to PCP fraction in laminar flow, agglomerated with overcharged protein particles at turbulent flow (14 LPM), and attracted to NCP fraction, thereby reducing protein enrichment. This research provides key optimization information for non-destructive legumes protein enrichment.
Acknowledgment: The project was funded through USDA-NIFA-AFRI Grant #2020-67021-31141.
|
Progress 09/01/21 to 08/31/22
Outputs
Target Audience:The target audiences of this reporting period was one African/American undergraduate student, one female graduate student, chemical and biotechnology companies (such as Sigma Aldrich, Fischer Scientific, VWR), our industry partner (Canadian International Grains Institute) and scientific community audiences of food engineers and food scientist. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Graduate (PhD level) and undergraduate students have been participated and involved in this research project related to the development of the Tribo-electrostatic separation technology for legumes and cereals. All students were mentored by providing not only scientific skills but also professional development, career planning and communication skills, the details of which are summarized below: Scientific and technical skills: All students attended and satisfied the mandatory laboratory safety orientation which is held by the College of Engineering and Architecture (CEA) at Howard University. All researchers contributed to research on developing a water-free triboelectrostatic separation approach and to explore the tribo-charging behavior of agro-materials based on their physiochemical and operational conditions. During this research project, the students developed expertise in electrostatic separation technology, tribo-charge measurement techniques, compositional analysis (protein and starch) as well as particle size measuremnet techniques. I will continue training students to effectively perform related biochemical analysis (SDS-PAGE) and food functionality (protein solubility, emulsifying and foaming properties) techniques as well as 3D food printing. My PhD studnet was trained by the PI to develop expertise in using SAS software to statistically analyze and optimize the experimental results obtained in the lab. The PI has extensive experience in working with SAS software and will be responsible for training all researchers in the lab. Communication skills, career planning and professional development: All students supposed to attend weekly in-person meetings to present their experimental and statistical modeling results. Group meetings with all trainees was held where they present a summary of their research findings and other members provide input. I provided comments, identify and resolve any difficulties carrying out their research tasks. My undergraduate student was encouraged to attend workshops on career advising, applying for academic jobs and graduate school, and CV preparation. I have supported all my undergraduate students to apply for graduate schools. My PhD student on this project is currently on her second year (joined my lab early August 2021). She has submitted one journal manuscript into Powder Technology Journal on Statistical optimization of yellow pea protein enrichmnet during Tribo-electrostatic separation approach. She has presented her computational and experimental results in two different conferences by American Oil Chemists' Society (AOCS) in May (In-person) and October (online) 2022. She has published a review manuscript in INFORM magazine (AOCS), and currently working on prepration of another research manuscript to be submitted to reputable Journals. How have the results been disseminated to communities of interest?The results obtained on oat grain cereals as part of Objectives 1 and 2 of this project have been published in "Food Science and Emerging Technologies Journal" in July 2022. The results on optimization of protein enrichmnet from yellow pea flour through tribo-electrostatic separation process (Objectives 1 & 2) have been published on "Powder Technology Journal". The summary of the results obtained on Oat grains and yellow pea was also published in INFORM maganzine (AOCS journal) in September 2022. Wehave also presented the obtained yellow pea results thorugh an oral (in-person) presentation in 2022AOCS (Amerian Oil Chemists' society) Annual Meeting (Processing Devision) in May, 2, 2022 as well as online presentation duringAOCS Sustainable Protein Forum in October, 2022. The details of all these Journal publications are provided here: Thomas, J., S. Ghadiri Gargari, S. Tabtabaei(2022) "Tribo-electrostatic Separation of Yellow Pea and its Optimization Based on Milling Types and Intensity." Powder Technology, IN PRESShttps://doi.org/10.1016/j.powtec.2022.118169 Ghadiri Gargari, S., and S. Tabtabaei (2022) "Green protein tribo-electrostatic fractionation: a state-of-the-art method." INFORM magazine, 4034492, September 2022. https://www.informmagazine-digital.org/informmagazine/library/item/september_2022/4034491/ Konakbayeva, D, B. Kuspangaliyeva, A. R. Rajabzadeh, S. Tabtabaei(2022). "Separation Behavior of Sieved Endosperm-Enriched Oat Fractions vis Tribo-electrostatic Approach" Innovative Food Science and Emerging Technologies, 80, 103098. https://doi.org/10.1016/j.ifset.2022.103098. The details of all these conference presentations are provided here: Ghadiri Gargari, S., and S. Tabtabaei (2022). Tribo-electrostatic Separation (TES) Behavior of Starch-rich Yellow Pea Flour in Response to TES Processing Parameters and Milling Procedure. AOCS Sustainable Protein Forum, Chicago, IL USA, October 4-6 (Online). Ghadiri Gargari, S., J. Thomas, S. Tabtabaei (2022). Development and Optimization of Tribo-electrification Separation Process for Dry Fractionation of Yellow Pea Flour. AOCS Annual Meeting, Atlanta, GA, USA, May 2 (Oral Presentation). What do you plan to do during the next reporting period to accomplish the goals?During the next year (2022-2023) of the project, we plan to fully accomplish the tasks proposed in Objective 1. As part of Objective 1 and to effectively examine the tribo-charging behavior of single-component protein and starch particles, we started by interrogating the chargeability of single-component protein and starch under different operational conditions. To achieve this goal, we did set-up a fluidized bed connected to the Faraday cup to pneumatically flow particles through tribo-charger tubes of different sizes and materials to effectively assess the role of air flow rate, powder dosing rate, tribo-charger size and material. Model protein and starch particles (aw ≈ 0) were initially placed in the fluidized bed on top of the air distributor screen. Dry air was introduced at the bottom of the bed to pass the suspended particles into the tribo-charger tube before dispensing them into Faraday cup connected to an electrometer for specific charge (nC/g) measurements. These charge measurement studies were performed at laminar air flow rate of 7LPM using 50-cm, 105-cm and 150-cm nylon, copper, PVC and PTFE tubes having 3/16" internal diameter. The results showed different chargeability of particles using different materials. All particles acquired highest charge-to-mass ratios at lower particle concentrations inside the tubes. Both protein and starch particles were charged negatively in contact with Nylon and among them starch has obtained the largest negative charge in contact with Nylon material. In contact with copper, all starch particles were charged negatively while protein particles acquired positive charges. In contact with PVC and PTFE, all particles charged positively, but protein particles acquired significantly higher charge to mass ratios (nC/g) compared to starch granules. In 2023: (1) We will continue the charge measurement studies to interrogating the chargeability of protein and starch at different air flow rates and tube diameters; (2) We will also analyze the particle sizes of all tested samples to be able to convert specific charge values (nC/g) to charge density values (nC/m2) to clearly understand the relevance of charge to particle size vs. surface chemistry; (3) We will analyze the charging behavior of the binary protein-starch mixtures and assess their separation behavior based on initial protein content under consistent operating conditions. We expect to finish the proposed task of Objective 1 by September 2023. Now that the results of Objective 2 were finalized, during 2022-2023 period, we will start the preliminary experiments on assessing the food functionality and 3D printing behavior of the fractionated yellow pea flour (Objectives 3 & 4). Our 3D food printer was purchased in January 2022 and set-up in the lab. My PhD student was fully trained to use the instrument. We are ready to get some preliminary results in the reporting period of 2022-2023 on 3D food printing, and we will continue our studies on this aspect during the last year of the project (i.e., 2023-2024).
Impacts
What was accomplished under these goals?
We have almost accomplished the tasks proposed as part of Objective 2 to study and optimize the separation behavior of oat groats and yellow pea flours under different milling conditions, air flow rates and electrostatic field strength. As part of Objective 2 and to effectively investigate the classification behavior of starch-rich legumes and cereals into protein- and starch-enriched fractions through TES, we started evaluating the separation behavior of oat groat particles as a cereal representative. Oat groats were purchased from Honyeville Inc. (Ogden, UT, USA) and used as the starting material for our proposed tribo-electrostatic separation approach using my newly custom-designed separator consisting of the fluidized bed, tribo-charger tube and clear plexiglass/polycarbonate separation chamber (122 cm height × 61 cm weight × 61 cm length) with two copper plate electrodes that the distance between those can be easily adjustable. The flour particles were initially suspended by the dry air stream inside the fluidized bed and directed to the PTFE tribo-charger tube before being separated in the chamber according to the acquired surface charge. This TES approach allowed us to separate positively charged particles from negatively- and non-charged particles. Following each separation experiments, three different fractions were collected form the separation chamber: (1) the fraction attached to the negatively-charged electrode plate; (2) the fraction attached to the positively-charged electrode plate; and (3) the noncharged fraction fell to the bottom of the separation chamber. The separation experiments were performed using PTFE tribo-charger tube with 3/16" internal diameter and 150-cm length. The separation processes were performed at two different air flow rates of 7 LPM (equivalent to laminar flow) and 15 LPM (equivalent to turbulent flow) and three different plate voltages of ±1 and ±7.0 kV. All collected fractions were analyzed for protein content and protein separation efficiencies. The fractions were also visualized by SEM and their particle sizes were also measured by producing their particle size distribution curves (volume% vs. Particle size, μm). During initial stages of experiments, we have realized that the fluidization of oat groat particles in the fluidized bed and the tribo-charging tube is very difficult due to the presence of large bran particles. Therefore, we have started sieving oat groat particles as a dry pre-treatment step. Therefore, through this process, oat groats were initially sieved at six different aperture sizes of 53 to 425 μm, resulting in the production of twelve different fractions including six starch-rich fractions as well as six bran-rich fractions among which the bran-rich fractions had significantly higher protein concentration (15.5 - 19.6%) compared to the starch-rich fractions (9.7 to 14.0%). We did also analyze the chargeability of all sieved fractions to understand how the charging behavior of these starch-rich and bran-rich particles are affected by their size and protein content under laminar and turbulent air flow rates. Bran-rich sieved particles despite their large particle sizes were acquired higher charge-to-mass (nC/g) ratios compared to starch-rich sieved fractions at the laminar air flow rate in contact with PTFE tribo-charging tube. However, starch-rich sieved fractions exhibited totally different tribo-charging behavior at the turbulent (Re = 4182) air flow rate due to the large surface-to-volume ratio of their fine small particles that resulted in enhanced particle-wall collisions and eventually acquisition of higher specific charge values compared to their equivalent sieved bran-rich fractions. The separation behavior of one of the sieved starch-rich fractions produced at aperture size of 106 μm with protein content of 10.1% was further studied through tribo-electrostatic separation approach at different air flow rates and plate voltages, where its protein enrichment level and the tribo-charging behavior of the resulting fractions were studied under different operating conditions. The results of this study were published recently in the "Food Science and Emerging Technologies"Journal in July 202. During this study, the charging behavior of all electrostatically separated fractions were analyzed based on their compositions and particle sizes and the results were used to improve the separation behavior of sieved oat groats. As legume representative, we have fully studied and statistically optimized the separation behavior of yellow pea flour through tribo-electrostatic separation approach. Yellow pea flours milled using both pin and Ferkar milling techniques at two different intensities (i.e., screen sizes) was purchased from Canadian International Grain Institute (cigi) and separated in our lab to identify the effect of milling types and intensity along with other operating factors of air flow rate and plate voltages on the purity and efficiency of the protein enrichments. The statistical optimizationresults collected as part of this study showed that yellow pea particles milled using pin milling system at lower screen sizes resulted in production of more pure protein concentrates after tribo-electrostatic separation approach. Generally, laminar gas flow rates and high plate voltages were found effective operating factors in purifying legumes, and we plan to better assess the chargeability behavior of separated fractions. We have presented part all these results through oral and online poster presentations at AOCS annual meeting (2022) and AOCS Sustainable Protein Forum in October 2022. All of these statistical optimization results were collected and published in "Powder Technology" journal. We are currently in the final process to prepare another research manuscript on the effect of operating conditions (i.e., milling types, intensity, air flow and plate voltage) on the enrichment level, particle size, SEM imaging, and charging behavior of the yellow pea protein particles in the separation chamber. We are expecting to submit this manuscript by end of January 2023.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2022
Citation:
Dinara Konakbayeva, Botagoz Kuspangaliyeva, Amin Reza Rajabzadeh, Solmaz Tabtabaei,
Separation behavior of sieved endosperm-enriched oat fractions via tribo-electrostatic approach,
Innovative Food Science & Emerging Technologies,
Volume 80,
2022,
103098,
ISSN 1466-8564,
https://doi.org/10.1016/j.ifset.2022.103098.
(https://www.sciencedirect.com/science/article/pii/S1466856422001837)
Abstract: Endosperm-enriched oat fraction passed through 106-?m aperture size sieving of oat groats was further processed by dry and chemical-free tribo-electrostatic separation approach for protein enrichment. The sieved oat flour consisting of both bran and endosperm particles was fluidized in dry air to be tribo-charged in a polytetrafluoroethylene (PTFE) tube before being separated under an external electric field into protein-rich and protein-depleted fractions. The effects of airflow rate and electric field strength were assessed by conducting fifteen tribo-electrostatic separations at five different plate voltages of �1, �3, �7, �12, and���15�kV, as well as three different airflow rates of 7, 10, and 14�l per minute (LPM), providing laminar, transient, and turbulent conditions in the tribo-charger tube, respectively. All fractions attracted to the negatively charged plate (i.e., NCP fraction) were enriched in protein. However, the fractions absorbed on the positively charged plate (PCP fraction) or collected by gravity at the bottom of the separation chamber (i.e., CB fraction) were all depleted of proteins. Higher protein enrichments were observed for NCP fractions at laminar airflow rate, where the lowest yields and protein separation efficiencies were obtained. Increasing plate voltages slightly reduced the NCP fractions' protein content but significantly improved their yields and protein separation efficiencies. Therefore, a laminar airflow rate of 7 LPM and a high plate voltage of �12�kV was selected as the best separation conditions for sieved oat flour. The SEM images of the NCP fraction obtained at 7 LPM and���12�kV showed the presence of bran and endosperm particles, while the PCP and CB fractions were depleted of bran particles. The full compositional analysis of the fractions produced at 7 LPM and���12�kV conditions showed the highest percentage of dietary fiber content in the PCP fraction. A negative correlation was observed between the protein content and mean particle size (D50) of the electrostatically separated fractions at the laminar and transient airflow rates. However, the protein-rich NCP fractions had the largest particle sizes at the turbulent airflow rate due to particle agglomeration and intense particle-particle interactions. An indirect offline approach was adapted to assess the charging behavior of all electrostatically separated fractions as functions of their protein content and particle sizes. All NCP fractions acquired higher charge density values than other fractions, which could be attributed to their higher protein contents. An online tribo-charge analysis method should be developed to assess the particle-particle interactions in the tribo-charger tube during electrostatic separation.
Keywords: Tribo-electrostatic separation (TES); Oat groats; Sieving; Protein; Starch; Specific charge; Charge density; Tribo-charging behavior
- Type:
Journal Articles
Status:
Published
Year Published:
2022
Citation:
Jamaka Thomas, Sama Ghadiri Gargari, Solmaz Tabtabaei,
Tribo-electrostatic separation of yellow pea and its optimization based on milling types and screen sizes,
Powder Technology,
2022,
118169,
ISSN 0032-5910,
https://doi.org/10.1016/j.powtec.2022.118169.
(https://www.sciencedirect.com/science/article/pii/S0032591022010506)
Abstract: A tribo-electrostatic separation was developed to produce protein concentrates from yellow pea flour. A mixed-level full factorial experiment followed by a multiple linear regression model was developed to assess the impacts of airflow rate, plate voltage, milling type, and screen size as operating factors on protein content, separation efficiency, and yield of the protein-enriched concentrates. Except for plate voltage, all factors showed significant impacts on protein content. The interaction of plate voltage and milling screen size was significant in protein content. Plate voltage was the only main effect statistically impacting protein separation efficiency; however, polynomial interactions of flow rate with plate voltage and flow rate with milling type and screen size were significant. The optimal parameters were laminar flow at �6.5?kV using pin-milled flour at the smallest tested milling screen size, which resulted in protein content of 57.1% and separation efficiency of 62%. Theoretical predictions agreed with experimental data.
Keywords: Tribo-electrostatic separation; Yellow pea; Pin milling; Ferkar milling; Milling screen size
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2022
Citation:
Gargari, Sama Ghadiri, Jamaka Thomas, and Solmaz Tabtabaei. "Development and statistical optimization of a tribo-electrification separation process for dry fractionation of yellow pea flour." JOURNAL OF THE AMERICAN OIL CHEMISTS SOCIETY. Vol. 99. 111 RIVER ST, HOBOKEN 07030-5774, NJ USA: WILEY, 2022.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2022
Citation:
Ghadiri Gargari, S., and S. Tabtabaei (2022). Tribo-electrostatic Separation (TES) Behavior of Starch-rich Yellow Pea Flour in Response to TES Processing Parameters and Milling Procedure. American Oil Chemists' Society (AOCS) Sustainable Protein Forum, Chicago, IL USA, October 4-6 (Online).
- Type:
Journal Articles
Status:
Published
Year Published:
2022
Citation:
Ghadiri Gargari, S., and S. Tabtabaei (2022) Green protein tribo-electrostatic fractionation: a state-of-the-art method. INFORM magazine, 4034492, September 2022. https://www.informmagazine-digital.org/informmagazine/library/item/september_2022/4034491/
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Progress 09/01/20 to 08/31/21
Outputs
Target Audience:The target audiences of this reporting period wasone African/American undergraduate student, one female graduate student, chemical and biotechnology companies (such as Sigma Aldrich, Fischer Scientific, VWR), our industry partner (Canadian International Grains Institute) and scientific community audiences of food engineers and food scientist. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Graduate (PhDlevel) and undergraduate students have been participated and involved in this research project related to the development of the Tribo-electrostatic separation technology for legumes and cereals. All students were mentored by providing not only scientific skills but also professional development, career planning and communication skills, the details of which are summarized below: Scientific and technical skills: All students attended and satisfied the mandatory laboratory safety orientation which is held by the College of Engineering and Architecture (CEA) at Howard University. All researchers contributed to research on developing a water-free tribo-electrostatic separation approach and to explore the tribo-charging behavior of agro-materials based on their physiochemical and operational conditions. During this research project, the students developed expertise in electrostatic separation technology, tribo-charge measurement techniques, compositional analysis(protein and starch) as well as particle size measuremnet techniques. I will continue training students to effectively perform related biochemical analysis (SDS-PAGE) and food functionality (protein solubility, emulsifying and foaming properties) techniques as well as 3D food printing. My PhD studnet wastrained by the PI to develop expertise in using SAS software to statistically analyze and optimize the experimental results obtained in the lab. The PI has extensive experience in working with SAS software and will be responsible for training all researchers in the lab. Communication skills, career planning and professional development: All students supposed to attend weekly in-person meetings to present their experimental and statistical modeling results.Group meetings with all trainees was held where they present a summary of their research findings and other members provide input. I provided comments, identify and resolve any difficulties carrying out their research tasks. My undergraduate student wasencouraged to attend workshops on career advising, applying for academic jobs and graduate school, and CV preparation. I have supported all my undergraduate students to apply for graduate schools. My PhD student on this project was recently joined my lab (early August 2021). Our University was operated remotely during the 2020-2021 acedemic yearand CEAresearch labs were fully closed until early December 2020. Due to Covid-19 situation during 2020-2021, I had some difficulties in finding a PhD studnetstarting earlier. Therefore, the PhD studnet joined my lab in August 2021 and started working on this project. We will submit conference presentations for her to improve her communication and presentation skills and plan to submit a research manuscript in Spring 2022 based on the obtained experimental results collected in the lab and thestatistical modeling results of yellow pea. How have the results been disseminated to communities of interest?The results obtained on oat grain cereals as part of Objectives 1 and 2of this project have been published in "Separation and Purification Technology Journal". I have also presented the obtained oat grain cereal results thorugh an oral presentationin 2021 AOCS (Amerian Oil Chemists' society) Virtual Annual Meeting (Processing Devision) on 14 May, 2021. The details of these publications are provided here: Konakbayeva, D. and S. Tabtabaei* (corresponding author) (2021). "Assessing the Chargeability and Separability of Oat Groat Particles through Sieving Combined with Triboelectrification-based Approach." Separation and PurificationTechnology,278:119486.https://doi.org/10.1016/j.seppur.2021.119486 Konakbayeva D., S. Tabtabaei* (2021). Evaluating the Tribo-charging Behavior of Oat Bran and Endosperm Particles during Dry Electrostatic Separation Approach for Functional Protein Production. AOCS Annual Meeting and Expo (Online-May 14). https://doi.org/10.21748/am21.148 I have also presented part of the preliminary results obtained for tribo-electrostatic protein separation of yellow pea flours milled using both pin and ferkar milling techniquies at different intensities through online potser presenattionat 2021 IFT Annual Meeting and Food Expo that was performed online through FIRST (Food Improved by Research, Science and Technology), an AI-enabled digital platform launched by IFT inJuly 19-21. The detailed of this poster presentaion is provided here. At this step we, are continuing to complete the experimental results on protein enrichmnet of yellow pea followed by statisicall modelling to better understand the effect of milling type and its intensity onprotein enrichmnet of yellow pea as a model starch-rich legume. Thomas, J., S. Tabtabaei* (2021). The Protein Fractionation of Yellow Pea as Affected by Milling Styles and Electrostatic Forces. IFT Annual Meeting and Food Expo (Online) Jul 19-21 (Poster). What do you plan to do during the next reporting period to accomplish the goals?To achieve the remaining aims of objective 1 during next reporting period of 2021-2022, the following studies will be performed: As mentioned above, we have studied the charging behavior of the single-component model particles of protein and starch using tribo-charger tubes of different contact materials (nylon, copper, PVC and PTFE tubes) and different lengths (50-, 105- and 150cm) at constant laminar air flow rate of 7 LPM and tribo-charge tube diameter of 3/16", but at different particle concentrations. The results showed a relationship between the tribo-charging behavior of protein particles compared to starch particles in contact with different materials. We will continue these chargeability studies at turbulent air flow rate and tribo-charger diameters to fundamentally identify the impacts of several critical parameters on the charging behavior of protein and starch and to systematically learn the relationship among these parameters by performing linear regression model. We will also plan to assess the chargeability of protein particles based on their pI and intrinsic pH. Yellow pea protein isolate and wheat gluten have totally different isoelectric point values, pIs, of 4.5 and 7.5, respectively. This will allow us to compare their chargeability based on the difference between isoelectric point of the proteins and their intrinsic pH. We will also plan to examine the charging behavior of model protein-starch mixture particles at different concentrations. All model mixtures will be placed inside the fluidized bed and analyzed for specific charge measurements at different air flow rates and particle dosing rates using the tribo-charger tube with optimal size and material. Analyzing the mixtures chargeability will give us fundamental information of how the particle-particle and particle-substrate interactions will be influenced under different conditions of air flow rate and particle dosing rate. To achieve the remaining aims of objective 2,we will finalize the optimization and statistical modelling separation experiments of yellow pea and oat groats based on milling types and intensity and will expand the separation to other types of legumes and cereals selected as part of the proposal including wheat and barley flours as well as faba beans and lentil. This will help us to collect enough samples to study the functionality of the electrostatically enriched protein fractions as well as their extrudability and printability during the third year of the proposed project (i.e. 2022-2023).
Impacts
What was accomplished under these goals?
As part of Objective 1 and to effectively examine the tribo-charging behavior of single-component protein and starch particles, we started by interrogating the chargeability of single-component protein and starch under different operational conditions. To achieve this goal, we did set-up a fluidized bed connected to the Faraday cup to pneumatically flow particles through tribo-charger tubes of different sizes and materials to effectively assess the role of air flow rate, powder dosing rate, tribo-charger size and material. Model protein and starch particles (aw ≈ 0) were initially placed in the fluidized bed on top of the air distributor screen. Dry air was introduced at the bottom of the bed to pass the suspended particles into the tribo-charger tube before dispensing them into Faraday cup connected to an electrometer for specific charge (nC/g) measurements. These charge measurement studies were performed at laminar air flow rate of 7LPM using 50-cm, 105-cm and 150-cm nylon, copper, PVC and PTFE tubes having 3/16" internal diameter. The results showed different chargeability of particles using different materials. All particles acquired highest charge-to-mass ratios at lower particle concentrations inside the tubes. Both protein and starch particles were charged negatively in contact with Nylon and among them starch has obtained the largest negative charge in contact with Nylon material. In contact with copper, all starch particles were charged negatively while protein particles acquired positive charges. In contact with PVC and PTFE, all particles charged positively, but protein particles acquired significantly higher charge to mass ratios (nC/g) compared to starch granules. We will also continue the charge measurement studies to interrogating the chargeability of protein and starch at different air flow rates and tube diameters. We will also analyze the particle sizes of all tested samples to be able to convert specific charge values (nC/g) to charge density values (nC/m2) to clearly understand the relevance of charge to particle size vs. surface chemistry. We have not yet performed the charge studies of the binary protein-starch mixtures and plan to do so during the next reporting period. As part of Objective 2 and to effectively investigate the classification behavior of starch-rich legumes and cereals into protein- and starch-enriched fractions through TES, we started evaluating the separation behavior of oat groat particles as a cereal representative. Oat groats were purchased from Honyeville Inc. (Ogden, UT, USA) and used as the starting material for our proposed tribo-electrostatic separation approach using my newly custom-designed separator consisting of the fluidized bed, tribo-charger tube and clear plexiglass/polycarbonate separation chamber (122 cm height × 61 cm weight × 61 cm length) with two copper plate electrodes that the distance between those can be easily adjustable. The flour particles were initially suspended by the dry air stream inside the fluidized bed and directed to the PTFE tribo-charger tube before being separated in the chamber according to the acquired surface charge. This TES approach allowed us to separate positively charged particles from negatively- and non-charged particles. Following each separation experiments, three different fractions were collected form the separation chamber: (1) the fraction attached to the negatively-charged electrode plate; (2) the fraction attached to the positively-charged electrode plate; and (3) the noncharged fraction fell to the bottom of the separation chamber. The separation experiments were performed using PTFE tribo-charger tube with 3/16" internal diameter and 150-cm length. The separation processes were performed at two different air flow rates of 7 LPM (equivalent to laminar flow) and 15 LPM (equivalent to turbulent flow) and two different plate voltages of ±1 and ±7.0 kV. All collected fractions were analyzed for protein content and protein separation efficiencies. The fractions were also visualized by SEM and their particle sizes were also measured by producing their particle size distribution curves (volume% vs. Particle size, μm). During initial stages of experiments, we have realized that the fluidization of oat groat particles in the fluidized bed and the tribo-charging tube is very difficult due to the presence of large bran particles. Therefore, we have started sieving oat groat particles as a dry pre-treatment step. Therefore, through this process, oat groats were initially sieved at six different aperture sizes of 53 to 425 μm, resulting in the production of twelve different fractions including six starch-rich fractions as well as six bran-rich fractions among which the bran-rich fractions had significantly higher protein concentration (15.5 - 19.6%) compared to the starch-rich fractions (9.7 to 14.0%). We did also analyze the chargeability of all sieved fractions to understand how the charging behavior of these starch-rich and bran-rich particles are affected by their size and protein content under laminar and turbulent air flow rates. Bran-rich sieved particles despite their large particle sizes were acquired higher charge-to-mass (nC/g) ratios compared to starch-rich sieved fractions at the laminar air flow rate in contact with PTFE tribo-charging tube. However, starch-rich sieved fractions exhibited totally different tribo-charging behavior at the turbulent (Re = 4182) air flow rate due to the large surface-to-volume ratio of their fine small particles that resulted in enhanced particle-wall collisions and eventually acquisition of higher specific charge values compared to their equivalent sieved bran-rich fractions. One of the sieved starch-rich fractions produced at aperture size of 106 μm with protein content of 10.1% was further fractionated through tribo-electrostatic separation processes at laminra air flow rate and ±7.0 kV, where its protein content was sharply enhanced by ~80% equivalent to over 55% protein separation efficiency. The results of this study were published recently in the "Separation and Purification Technology" journal and were orally presented during 2021 AOCS annual meeting, as outlined in the "Products" section of the annual report. As legume representative, we have started separating yellow pea flours. Yellow pea flours milled using both pin and Ferkar milling techniques at two different intensities wereprovided by Canadian International Grain Institute (cigi) and separated in our lab to identify the effect of milling types and intensity along with other operating factors of air flow rate and plate voltages on the purity and efficiency of the protein enrichments. The preliminary results collected as part of this objective did show that yellow pea particles milled using pin milling system at lower intensity resulted in production of more pure protein concentrates after tribo-electrostatic separation approach. Generally, laminar gas flow rates and high plate voltages were found as effective operating factors in purifying legumes and we plan to better assess the chargeability behavior of separated fractions during th next reporting period. We have presented part of these preliminary results through online poster presentationat 2021 IFT (First 2021) and performed some kind of preliminary statistical analysis to model the experimental results. We are currently trying to finalize the experimental and statistical analysis of yellow pea separations to be able to publish the results in journal manuscripts.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2021
Citation:
Dinara Konakbayeva, Solmaz Tabtabaei,
Assessing the chargeability and separability of oat groat particles through sieving combined with triboelectrification-based approach,
Separation and Purification Technology,
Volume 278,
2021,
119486,
ISSN 1383-5866,
https://doi.org/10.1016/j.seppur.2021.119486.
(https://www.sciencedirect.com/science/article/pii/S1383586621011941)
Abstract: The possibility of fractionation of dehulled oat groat particles was assessed through combined sieving and tribo-electrostatic separation approach. Through this process, oat groats were initially sieved at six different aperture sizes of 53 to 425 ?m, resulting in the production of twelve different fractions including six starch-rich fractions as well as six bran-rich fractions among which the bran-rich fractions had significantly higher protein concentration (15.5⿿19.6%) compared to the starch-rich fractions (9.7⿿14.0%). A linear relationship (R2 = 0.9554) was found between protein content and mean particle diameters (D50) of all sieved fractions. The tribo-charging behavior of all sieved fractions was assessed as a function of particle size and protein content. Bran-rich particles despite their large particle sizes were acquired higher charge-to-mass (nC/g) ratios compared to starch-rich fractions at the laminar air flow rate (Re = 2091) in contact with polytetrafluoroethylene (PTFE) tribo-charging tube. To exclusively evaluate the tribo-charging behavior of the fractions as a function of protein content, the specific charge (nC/g) values were recalculated to charge density (nC/m2) values and a three-stage incremental trend was observed between charge density and protein content of the fractions at the laminar air flow rate. Starch-rich fractions exhibited totally different tribo-charging behavior at the turbulent (Re = 4182) air flow rate due to the large surface-to-volume ratio of their fine small particles that resulted in enhanced particle⿿wall collisions and eventually acquisition of higher specific charge values compared to their equivalent sieved bran-rich fractions. The starch-rich fraction sieved at aperture size of 106 ?m with protein content of 10.1% was further fractionated through single- and multi-stage tribo-electrostatic separation processes where its protein content was sharply enhanced by ~80% equivalent to over 55% protein separation efficiency.
Keywords: Sieving; Protein; Tribo-charging behavior; Tribo-electrostatic Separation; Starch; Particle size
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2021
Citation:
Tabtabaei, Solmaz, and Dinara Konakbayeva. "Evaluating the Tribo-charging Behavior of Oat Bran and Endosperm Particles During Dry Electrostatic Separation Approach for Functional Protein Production."
14 May, 2021
DOI:10.21748/am21.148
Conference: Virtual 2021 AOCS Annual Meeting & Expo
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